This invention relates to microchannel fluidic devices, such as an ink jet printhead, but more particularly, to support structures for supporting large channel plates while allowing fluids to flow through microchannels of a printhead.
As the size of printheads increases, the ink reservoir region of the channel plate of the printhead will also increase in size. This size increase may make the channel plate fragile and prone to cracking failure during etching, bonding or dicing. One solution is to divide the reservoir into a multiple smaller reservoirs. With reference to FIG. 1, a conventional ink jet printhead, generally indicated at 10, includes ink inlets 12, an ink reservoir 14, a channel plate 15 defining a plurality of channels 16, and support structure 18. The support structure 18 separates the reservoir 14 into multiple regions, but air bubbles caught in the reservoir 14 tend to pinch-off ink flow to the channels at the end 20 of the support structure 18. Reduced ink flow to channels is not acceptable when multiple small reservoirs are provided because the channels at the ends of the small reservoirs are in the middle of the printhead 10 and, as a result, may not be usable for printing. This phenomenon presents itself in other microchannel fluidic devices, a printhead being discussed herein as one example of an application of the present invention.
Accordingly, there is a need to provide support structure which will lend structural support to a channel plate while allowing ink or other fluid to flow to the channels in the middle of the channel plate.
An object of the present invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is attained by providing, in one application of the invention, an ink jet printhead including an ink reservoir having an inlet for receiving ink, a top portion and a bottom portion. A channel plate structure defines a plurality of channels in fluid communication with the reservoir for directing ink from the reservoir. Support structure is provided near the top portion of the reservoir and extends within the reservoir. The support structure is constructed and arranged to divide the reservoir into at least a pair of reservoir regions and to provide support to the channel plate structure while permitting substantially unobstructed ink flow to all of the channels at the bottom portion of the reservoir.
In accordance with another aspect of the invention a method of modifying a support structure for a channel plate of, by way of example, an ink jet printhead provides an ink reservoir having an inlet for receiving ink, a bottom portion and a top portion. A channel plate is provided having a plurality of channels to direct ink from the reservoir. The method includes providing support structure at the top portion of the reservoir so as to extend into the reservoir and having an end portion spaced from the bottom of the reservoir. The support structure is constructed and arranged to divide the reservoir into at least a pair of reservoir regions and to provide support to the channel plate. A portion of the support structure which extends into the reservoir is removed to define a remaining end portion of the support structure within the reservoir. The remaining end portion is spaced from the bottom portion of the reservoir a distance greater than a distance the end portion is spaced from the bottom portion of the reservoir, thereby permitting substantially unobstructed ink flow to all of the channels at the bottom portion of the reservoir.
In accordance with yet another aspect of the invention, a method of providing a support structure for a channel plate of an ink jet printhead provides an ink reservoir having an inlet for receiving ink, a bottom portion and a top portion. A channel plate is provided having a plurality of channels to direct ink from the reservoir. Support structure is disposed at the top portion of the reservoir so as to extend into the reservoir behind the channels. The support structure is constructed and arranged to divide the reservoir into at least a pair of reservoir regions, to provide support to the channel plate, and to permit substantially unobstructed ink flow to all of the channels.
Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts, and economics of manufacture, will become apparent upon consideration of the following description of illustrative embodiment and appended claims with reference to the accompanying drawings, all of which form a part of this specification.